In recent years, multifunctional-type mobile phones such as those represented by multifunctional mobile phone terminals (smartphones) have come into widespread use. With various applications installed, multifunctional mobile phone terminals achieve a variety of functions. Among those applications, many have a function such as that of an automotive navigation system, which has been conventionally built into an in-vehicle unit. As a result of this, these days, there has been an increasing desire to utilize such a function, which is mounted in a multifunctional mobile phone terminal, in an in-vehicle unit.
In connection with this, an electronic system is known in which an information terminal and an electronic unit such as an in-vehicle unit are able to communicate with each other through a plurality of communication systems (for example, see Patent Document 1). Furthermore, a vehicular communication system is known in which an application executed in a mobile terminal unit and an application executed in a vehicular communication unit are caused to operate cooperatively with each other, the mobile terminal unit and the vehicular communication unit being able to communicate with each other through a plurality of communication systems (for example, see Patent Document 2). Furthermore, a display system is known in which a mobile communication terminal and a display unit, which are able to communicate with each other through a plurality of communication systems, respectively transmit and receive pieces of information in accordance with their respective communication systems (for example, see Patent Document 3).